imx: add i.MX8 SoCs build info SIP(silicon provider) service support

This patch adds NXP i.MX8 SoCs' build info SIP support for easy debug.
With this function enabled, TF-A's commit hash can be showed in u-boot
debug console when booting up, when there is any issue which could be
related to TF-A, users can use the commit hash value to easily identify
which commit introduces the issue.
Signed-off-by: Anson Huang <Anson.Huang@nxp.com>

plat/imx/common/imx_sip_handler.c

@@ -7,6 +7,7 @@
 #include <stdlib.h>
 #include <stdint.h>
 #include <std_svc.h>
+#include <string.h>
 #include <platform_def.h>
 #include <common/debug.h>
 #include <common/runtime_svc.h>
@@ -137,3 +138,46 @@ int imx_misc_set_temp_handler(uint32_t smc_fid,
 {
 	return sc_misc_set_temp(ipc_handle, x1, x2, x3, x4);
 }
+
+static uint64_t imx_get_commit_hash(u_register_t x2,
+		    u_register_t x3,
+		    u_register_t x4)
+{
+	/* Parse the version_string */
+	char *parse = (char *)version_string;
+	uint64_t hash = 0;
+
+	do {
+		parse = strchr(parse, '-');
+		if (parse) {
+			parse += 1;
+			if (*(parse) == 'g') {
+				/* Default is 7 hexadecimal digits */
+				memcpy((void *)&hash, (void *)(parse + 1), 7);
+				break;
+			}
+		}
+
+	} while (parse != NULL);
+
+	return hash;
+}
+
+uint64_t imx_buildinfo_handler(uint32_t smc_fid,
+		    u_register_t x1,
+		    u_register_t x2,
+		    u_register_t x3,
+		    u_register_t x4)
+{
+	uint64_t ret;
+
+	switch (x1) {
+	case IMX_SIP_BUILDINFO_GET_COMMITHASH:
+		ret = imx_get_commit_hash(x2, x3, x4);
+		break;
+	default:
+		return SMC_UNK;
+	}
+
+	return ret;
+}

plat/imx/common/imx_sip_svc.c

@@ -40,6 +40,8 @@ static uintptr_t imx_sip_handler(unsigned int smc_fid,
 	case IMX_SIP_MISC_SET_TEMP:
 		SMC_RET1(handle, imx_misc_set_temp_handler(smc_fid, x1, x2, x3, x4));
 #endif
+	case  IMX_SIP_BUILDINFO:
+		SMC_RET1(handle, imx_buildinfo_handler(smc_fid, x1, x2, x3, x4));
 	default:
 		WARN("Unimplemented i.MX SiP Service Call: 0x%x\n", smc_fid);
 		SMC_RET1(handle, SMC_UNK);

plat/imx/common/include/imx_sip_svc.h

@@ -14,6 +14,9 @@
 #define IMX_SIP_SRTC			0xC2000002
 #define IMX_SIP_SRTC_SET_TIME		0x00
 
+#define IMX_SIP_BUILDINFO			0xC2000003
+#define IMX_SIP_BUILDINFO_GET_COMMITHASH	0x00
+
 #define IMX_SIP_WAKEUP_SRC		0xC2000009
 #define IMX_SIP_WAKEUP_SRC_SCU		0x1
 #define IMX_SIP_WAKEUP_SRC_IRQSTEER	0x2
@@ -35,6 +38,9 @@ int imx_otp_handler(uint32_t smc_fid, void *handle,
 int imx_misc_set_temp_handler(uint32_t smc_fid, u_register_t x1,
 			      u_register_t x2, u_register_t x3,
 			      u_register_t x4);
+uint64_t imx_buildinfo_handler(uint32_t smc_fid, u_register_t x1,
+			       u_register_t x2, u_register_t x3,
+			       u_register_t x4);
 #endif
 
 #endif /* __IMX_SIP_SVC_H__ */